Using laser processing methods, in particular laser cutting and laser welding, it is possible to process workpieces, in particular metal sheets, in a highly precise manner. However, during laser processing operations, persons in surrounding areas must be protected from the laser radiation.
Laser radiation may in particular damage a person's eyes. In this instance, it is not only direct radiation from the laser beam which is dangerous, but also scattered light which is emitted from a processing zone (e.g., the illuminated region) on the workpiece. Such direct radiation and scattered light can lead to permanent damage in the region of the retina or pupil. A particular danger involves lasers in the non-visible radiation range, in particular infrared lasers, since the incident light in the eye is not immediately noticed and in particular does not activate the lid closure reflex.
In order to protect operating personnel, a shield (e.g., an internal shield) can be arranged locally on the laser processing head of a laser processing machine. In some embodiments, a local shielding device on a laser processing head having two brush-like shielding units can be moved relative to each other.
Local shielding units can screen the laser light which is propagated from a processing zone radially (e.g., in a linear direction) in slow operating modes, but not in rapid operating modes with the reliability required for optical safety of operating personnel in the environment. Thus, the laser processing machine is often additionally provided with an external shield. The external shield includes a laser protection wall of material (e.g., sheet metal, wood, or special discs) which is impermeable to the laser radiation used. The laser protection wall surrounds the laser processing head and at least a portion of the laser processing machine. The space inside the laser protection wall is referred to as a danger region since scattered laser radiation can in principle pass through it.
In some embodiments, a laser processing machine is surrounded with a closed machine cabin. Discharge of laser radiation is thereby reliably prevented, and noise pollution in the environment is thereby reduced. Access to the laser processing machine for operating personnel (e.g., to perform set-up operations on the laser processing head) is provided through doors, which, during operation of the laser processing head have to be closed.
In certain embodiments, laser processing and punching machines are surrounded entirely by a laser protection wall which has to be opened (e.g., with telescope-like doors) to allow people to enter the danger region. A disadvantage of such arrangements is that, in order for people to enter the danger region, doors, gates, or the like have to be opened. After completing manual operations on the laser processing machine, before continuing operation of the laser processing head, these doors have to be closed again in order to ensure laser safety. Manual opening of these doors is time-consuming and troublesome, in particular when a free hand is or even both hands are required for this. Automatic door opening systems are expensive, and in most cases, also delay access to the laser processing machine (e.g., to the danger region), and in particular, to the laser processing head.